With well-known elliptic-dioptric headlamps comprising an elliptic reflector, a screen and a lens, the lens is designed for throwing the light beam from the reflector in such a way that it is almost fully directed to below the horizontal plane so that the luminous intensity above said plane is of a minimum value. This admittedly leads to a reduction of dazzling the drivers of passing cars but, onthe other hand, due to to a poor illumination, the perception of vertical traffic signs or signals is limited, since the brightness of communicative surfaces of such signs, if illuminated by such headlamps, becomes relatively low. Apart from this, such reduced luminous intensity above the light and darkness boundary does not enable the driver to sufficiently control his activity in the upper part of his operative space. This may negatively influence any travel on untreated and unlit roads, and particularly in the absence of the so-called silhouette vision created by the lights of passing cars.